Identification and comparison of microRNAs from mammary glands from two porcine breeds using Solexa deep-sequencing technology

Abstract Text:  A total of 19,426,468 and 18,702,492 mappable reads were obtained from the RX_J (mammary gland of Jinhua pig) and RX_Y (mammary gland of Yorkshire pig) libraries, respectively. There were 8,688,717 and 5,548,775 reads of the total mappable reads in RX_J and RX_Y libraries mapped to the porcine miRs in miRBase version 19.0. In our study, the results showed that a total of 212 miRNAs were differentially expressed between the two libraries (P<0.05), of which 46 were down-regulated and 166 were up-regulated in RX-Y compared to the RX-J. Among the up-regulated miRNAs, ssc-miR-21_R+1 had the highest expression, while in the down-regulated miRNAs, ssc-miR-30a-5p_R+2 had the highest expression level, and followed by ssc-let-7a. The expression levels of 9 differentially expressed miRNAs were elected randomly and validated in RX-J and RX-Y using real-time quantitative RT-PCR (P<0.05). The expression pattern was consistent with the Solexa sequencing results.

Keywords:

mammary gland

miRNA

deep-sequencing technology